Chemotherapy Alone is Promising for Pediatric Medulloblastoma
According to results recently published in the New England Journal of Medicine, treatment with chemotherapy alone appears to be an effective treatment choice in children under the age of 3 years with medulloblastoma, particularly for patients whose cancer is completely removed with surgery.
Medulloblastoma is the most common type of brain cancer that occurs in children. Approximately 25%-35% of patients diagnosed with medullablastoma are under the age of 3 years. Standard treatment for medulloblastoma typically includes the surgical removal of as much of the cancer as possible, followed by chemotherapy and radiation therapy. Chemotherapy is utilized to kill cancer cells that may be remaining in the body following surgery and radiation therapy is utilized to kill cancer cells in the area of the brain. Unfortunately, since children under the age of 3 have immature brains, radiation therapy is associated with cognitive defects that continue to increase for years and are often irreversible.
A multi-institutional clinical trial was recently conducted to evaluate the elimination of radiation therapy in the treatment of medulloblastoma in order to reduce the cognitive side effects associated with its use. The recent clinical trial was conducted in 31 pediatric oncology centers between 1992 and 1997. This trial included 43 children with medulloblastoma under the age of 3 years who were treated with chemotherapy following the surgical removal of their cancer. Patients received both intravenous (delivered into a vein) chemotherapy, as well as chemotherapy delivered directly into the brain. Researchers were hopeful that chemotherapy delivered into the brain may be used in place of radiation therapy to the brain. The chemotherapy agent methotrexate was used for delivery into the brain and the combination of chemotherapy agents, cyclophosphamide, vincristine, carbloplatin and etoposide, was used for intravenous delivery. At diagnosis, 31 (72%) children had no evidence of cancer spread and 12 (28%) children had evidence of cancer spread. Among the group of patients who had no evidence of cancer spread, 17 had their cancer completely removed with surgery (complete resection), while 14 patients had their cancer only partially removed with surgery (incomplete resection).
At 5 years, overall survival and progression-free survival for the group of patients without evidence of cancer spread at diagnosis was 93% and 82%, respectively, for those who had a complete resection, and 56% and 50% for those who had an incomplete resection. Among the group of patients who had evidence of cancer spread at diagnosis, overall survival and progression-free survival at 5 years was 38% and 33%, respectively. Patients whose cancer was classified as “desmoplastic” had a significantly improved overall and progression-free survival than those with “classic” medulloblastoma. Furthermore, patients under the age of 2 years had a worse prognosis than those diagnosed between the ages of 2 and 3. The IQ of patients in this study was lower than that of their healthy counterparts; however, it was higher than those of comparable patients who had received radiation therapy in previous studies. Sixteen patients received further therapy following cancer progression and 6 became long-term survivors. Two of these surviving patients had received chemotherapy, two had received radiotherapy and two had received both radiation therapy and chemotherapy.
The researchers concluded that initial treatment consisting of intravenous and intrathecal chemotherapy may be just as effective as chemotherapy plus radiation therapy in patients under the age of 3 diagnosed with medulloblastoma, without the associated side effects of radiation therapy. Patients who achieved the greatest long-term outcomes with chemotherapy only were those with no evidence of cancer spread upon diagnosis and those who had a complete resection. Parents of children diagnosed with medulloblastoma may wish to speak with their physician regarding their child’s individual risks and benefits of treatment with chemotherapy only or the addition of radiation therapy.
Reference: Rutkowski S, Bode U, Deinlein, et al. Treatment of early childhood medulloblastoma by postoperative chemotherapy alone. New England Journal of Medicine. 2005;352:978-986.